Why Your Allergies Are Getting Worse Every Year

If spring allergy season feels worse than it was a decade ago, you are not being dramatic. The data backs you up. Pollen seasons are starting earlier, lasting longer, and delivering higher total pollen counts than they did in previous generations. The cause is not a mystery, and understanding it can help you get ahead of the misery rather than just enduring it.

The Season Has Gotten Measurably Longer

Climate Central analyzed pollen data across 173 U.S. cities and found that the frost-free growing season, the window during which plants can grow and release pollen, has extended by an average of 21 days since the early 1970s. Some regions have seen even larger increases. The Northwest has gained more than 30 additional frost-free days on average.

A longer frost-free season means trees begin releasing pollen earlier in spring, grass pollen arrives sooner in late spring, and ragweed continues producing pollen further into fall. The result is a pollen calendar that has expanded at both ends, squeezing the windows of relatively pollen-free air that allergy sufferers once depended on.